RE: [PATCH bpf-next v3 03/12] bpf: tcp: move assertions into tcp_bpf_get_proto

John Fastabend
2020-03-06T15:25:44Z

Lorenz Bauer wrote:
> We need to ensure that sk->sk_prot uses certain callbacks, so that
> code that directly calls e.g. tcp_sendmsg in certain corner cases
> works. To avoid spurious asserts, we must to do this only if
> sk_psock_update_proto has not yet been called. The same invariants
> apply for tcp_bpf_check_v6_needs_rebuild, so move the call as well.
>
> Doing so allows us to merge tcp_bpf_init and tcp_bpf_reinit.
>
> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>

Small nit if you update it just carry the acks through.

Acked-by: John Fastabend <john.fastabend@gmail.com>

> skb_verdict = READ_ONCE(progs->skb_verdict);
> @@ -191,18 +191,14 @@ static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
> ret = -ENOMEM;
> goto out_progs;
> }
> - sk_psock_is_new = true;
> }
>
> if (msg_parser)
> psock_set_prog(&psock->progs.msg_parser, msg_parser);
> - if (sk_psock_is_new) {
> - ret = tcp_bpf_init(sk);
> - if (ret < 0)
> - goto out_drop;
> - } else {
> - tcp_bpf_reinit(sk);
> - }
> +
> + ret = tcp_bpf_init(sk);
> + if (ret < 0)
> + goto out_drop;
>
> write_lock_bh(&sk->sk_callback_lock);
> if (skb_progs && !psock->parser.enabled) {
> @@ -239,12 +235,9 @@ static int sock_map_link_no_progs(struct bpf_map *map, struct sock *sk)
> if (IS_ERR(psock))
> return PTR_ERR(psock);
>
> - if (psock) {
> - tcp_bpf_reinit(sk);
> - return 0;
> - }
> + if (!psock)
> + psock = sk_psock_init(sk, map->numa_node);
>
> - psock = sk_psock_init(sk, map->numa_node);
> if (!psock)
> return -ENOMEM;

also small nit this reads,

if (!psock)
psock = ...
if (!psock)
return -ENOMEM

how about,

if (!psock) {
psock = ...
if (!psock) return -ENOMEM;
}